The Pythagorean Theorem

9th Grade50 minutes

Learning Objective

I can use the Pythagorean theorem to find the missing side length of a right triangle.

Key Concepts

The Pythagorean theorem, represented as a² + b² = c², is used to find the missing side length of a right triangle, where 'c' is the hypotenuse and 'a' and 'b' are the legs.

To find the length of a missing leg, you can plug in the known values into the Pythagorean theorem and isolate the variable representing the missing leg by using inverse operations such as subtraction and finding the square root.

When the result of the square root is not a perfect square, you can express the answer as a square root or approximate it as a decimal rounded to a certain place value, like the hundredths place.

Practice Questions

This lesson includes 11 practice questions to reinforce learning.

View questions preview

1. What formula is used to represent the Pythagorean Theorem?

2. In the Pythagorean Theorem, what does 'c' represent?

3. A right triangle has legs of length 3 and 4. What is the length of the hypotenuse?

...and 8 more questions

Educational Video

Pythagorean Theorem: Finding the Length of a Missing Leg | Math with Mr. J

Math with Mr. J

Create Your Own Lesson

Generate a custom lesson plan like this one in minutes with Insta~Lesson